In a large pot over medium heat, melt 2 tablespoons of butter until foamy. Add 1 diced onion and 1 sliced leek, sautéing for about 5 minutes or until they’re soft and translucent.

Add 3 diced medium-sized starchy potatoes to the pot, stirring well to coat them in the buttery goodness. Cook for an additional 3 minutes.

Pour in 4 cups of vegetable broth, ensuring all the ingredients are submerged. Bring the mixture to a vigorous boil for around 5 minutes.

Reduce the heat to a gentle simmer. Stir in 1 cup of chopped green cabbage and 1 cup of chopped kale. Cover and let it simmer for 15-20 minutes.

Remove the pot from heat and use an immersion blender to puree the soup to your desired consistency.

Return the pot to low heat and stir in 1 cup of milk or your preferred plant-based milk. Season with salt, pepper, and a pinch of nutmeg.

Ladle the soup into bowls and garnish with sliced green onions. Serve hot.